This invention relates to a method and apparatus for the assembly and testing of intricate components. One example of the use of such a method and apparatus is in the assembly and testing of wiring harnesses for vehicles, such as automobiles. Such wiring harnesses require the assembly and testing of a plurality of intricate electrical components, such as electrical wires, resistors, capacitors, switches and fuses. The method and apparatus of this invention is addressed to two broad functions: assembly and testing. The testing function is conducted during the various stages of assembly, rather than after assembly has been completed.
The assembly and testing of wiring harness requires that the wiring harnesses be tested for electrical continuity and that the wiring harnesses be free of electrical open, crossed, shorted and incomplete circuits. For example, among the typical problems which may occur during the assembly of wiring harnesses are: Wires may be connected to the wrong pins in a connector. Wires may be connected to the wrong connector. Insulation strips may be impropertly assembled at the connector and allow two wires to short circuit. A connector may have defective contacts. Contacts of a wire may not be fully inserted into the connector. In prior art assembly lines, when wiring harnesses are fully assembled and then tested, the wiring harnesses which are found defective must be discarded or set aside for further analysis and repair.
Typical prior art apparatus and methods, such as U.S. Pat. No. 2,768,428 to MacGregor et al., use a synchronized conveyor belt system and only test for electrical misconnection or continuity. Some prior art apparatus and methods allow the wiring harness to continue along the assembly to completion of assembly before defects are corrected. In addition, the use of an overhead projector above a work surface to provide a lighted arrow to direct the assembly of electrical components, such as wiring harnesses, has been disclosed in promotional literature by Ragen Precision Industries, Inc., 9 Porete Avenue, North Arlington, N.J.